Balsamic vinegar is not all alike. Most homes in America that have balsamic vinegar in the pantry are not even aware of the variations in the product. Commercial grade balsamic vinegar is what most people buy.
Commercial balsamic vinegar (or balsamic vinegar of Modena) is basically an imitation of the original traditional balsamic vinegar. Made with wine vinegar, added coloring, and thickeners, these products are made to copy the thick texture and the sweet taste of aged traditional balsamic vinegar. The commercial products are not aged and are thus able to be produced on the large scale.
Aceto Balsamico Tradizionale, or traditional balsamic vinegar, is a product requiring many years of fermentation. In the European Union, 12 years is the minimum fermentation period for any balsamic vinegar to be labeled as traditional balsamic vinegar. In Modena, Italy, they identify bottles of vinegar aged for at least 12 years with a cream-colored bottle cap. A magenta-colored cap indicates fermentation for 25 years or more.
In Reggio Emilia, Italy, a red label indicates vinegar that has aged for 12 years or more, a silver label for 18 years or more, and a gold label for 25 years or more. These top quality products are derived specifically from the Lambrusco or Trebbiano grapes. Traditional balsamic vinegar is first cooked into a reduction and then transferred every year or two into successively smaller barrels as it evaporates, ferments, and oxidizes. The wood barrels made of cherry, acacia, chestnut, ash, oak, or mulberry give a woody element to the sweet and sour flavor of the grapes.
Condiment balsamic vinegar is sometimes made in the traditional way, but for less than the 12 years required for label as traditional. It could also be made in the traditional way but diluted with reduced grape juice. Sometimes it is a blend of traditional balsamic vinegar and commercial balsamic vinegar. Thus the product is generally of a higher quality than the commercial product alone, but is a good deal more affordable than pure traditional balsamic vinegar.